What happens to the day after it rains schedule, is the work just compounded? do ALL the customers get serviced? do some get skipped? I pretty much have a full four days schedule, with one day for rain or makeup, but if it rains two days I'm screwed, that's what I'm concerned about next season.

That doesn't happen much. But it happen at least twice this summer. Each crew has four full days and Fridays are half full. So if the day is a full wash out, we expand the work day (crews have both days on the schedule). They do as many as the can and we will usually catch up in about 3 days. Same thing if it rains two days.
We do get calls from the customers, so in the future I'm going to work out a way to contact them. Some of the customers just don't understand. "It rained Monday and Tuesday, but I'm on your Wednesday schedule so why aren't you here"